过量汞进人体内能引起E．

A. They differ in their standards of choosing husbands.
B. They can choose their husbands by themselves.
C. They have different attitudes towards love.
D. They are different from each other in their sense of responsibility.

A. be
B. being
C. been

A disease can die, but never come back.
B. Cholera is a disease that doesn't cause infections.
C. A comeback disease is only restricted in one area.
D. The comeback of a disease is due to a combination of many factors,